#include <iostream>
#include <vector>
using namespace std;

int n;
int cnt = 0;
vector<bool> items(10);

int main()
{
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < 3; j++)
        {
            int k;
            cin >> k;
            k--;

            if (items[k] == true)
            {
                cnt++;
            }
            items[k] = items[k] ^ 1;
        }
    }
    int etc = 0;
    for (int i = 0; i < items.size(); i++)
    {
        etc += items[i];
    }
    cout << cnt + etc / 4;
}